Common measures used to control exposure to hazardous substances

A hazardous substance management programme can include any combination of the following.

Good design and installation practice

• totally enclosed process and handling systems
• separation of the hazardous process from the operators or from other processes
• plant, processes or work systems that minimise the generation of hazardous dusts, fumes and so on, or suppress or contain them, and that limit the area of contamination in the event of spills and leaks
• partial enclosure with local exhaust ventilation
• local exhaust ventilation
• sufficient general ventilation

Work systems and practices

• fewer workers exposed, and non-essential access excluded
• shorter periods of exposure
• regular cleaning of contaminated walls, surfaces and so on
• proper use and maintenance of engineering controls
• ways to store and dispose of hazardous substances safely

Personal protection

• where the measures above are not enough, suitable PPE until the risk is eliminated or reduced to a level that is no threat to health
• a ban on eating, chewing, drinking and smoking in contaminated areas
• adequate washing and changing facilities and storage for clothing, with everyday clothing kept apart from work clothing, and arrangements for laundering contaminated clothing
• signs and notices
• adequate emergency arrangements

Exposure to the following types of hazardous substance may call for suitable health surveillance:

• substances (dusts, fibres, solids, liquids, fumes, gases) with a recognised systemic toxicity, meaning an insidious poisonous effect
• substances known to cause chronic effects, such as occupational asthma
• substances known to be sensitisers, irritants or allergens
• substances known or suspected to be carcinogens, teratogens, mutagens or harmful to reproductive health (reprotoxic)
• other substances likely to harm health under particular work conditions or when ambient conditions fluctuate

Where workers are exposed to specific hazards, health surveillance should include biological monitoring for the early detection of health effects when:

• a valid and generally accepted reference method exists
• it can be used to identify workers who need a detailed medical examination, subject to the worker's consent
• it may be needed to detect exposure levels and early biological effects and responses

Employers should make sure that workers receive enough specific and systematic training and information on:

• the nature and degree of the hazards and risks from hazardous substances that may arise, particularly in an emergency
• protecting their own safety and health and that of others from hazardous substances that may be present, in particular through correct and prescribed methods of handling, storage, transport and waste disposal
• the correct and effective use of control and protection measures and of PPE

Additional controls for carcinogens, mutagens and asthmagens

Exposure to carcinogens, mutagens and asthmagens should be prevented. If that is not possible, the following controls apply in addition to the general precautions above:

• totally enclosing the process and handling systems, unless this is not reasonably practicable
• a ban on eating, drinking and smoking in areas that may be contaminated by carcinogens or mutagens
• cleaning floors, walls and other surfaces at regular intervals and whenever necessary
• designating the areas and installations that may be contaminated by carcinogens or mutagens, with suitable and sufficient warning signs
• storing, handling and disposing of carcinogens or mutagens safely, including the use of closed and clearly labelled containers

Summary notes for Element 7 · Cheat sheet · Glossary. A study aid, not published or endorsed by NEBOSH.